It's so rare to have a great quality single player game these days. Wolfenstein: TNO proved it is still viable. The amount of detail in that game is unreal, and it has a great score as well. Doom 2016 further proved this. It had multiplayer but only as an afterthought. I think too many games focus on multiplayer these days. Look at Youngblood for example.
I've gotten out of gaming. Been running gnu/linux exclusively for years, and I've just occupied myself other ways. I'd love to play some quality sp games with a good story though. Is there any decent sp mod scene for games anymore? RTCW and HalfLife had some awesome mods/extensions, some of which were equal to the original game imo. I loved They Hunger for HalfLife, and there were lots of fun single mission extensions for both games.
I think people got out of it cause it's hard. Takes a lot more work to develop a story along with the 3d geometry. Maybe lack of player interest too? I'm not that interested in mp. *I'd rather chillout to a good story, and get lost in another world for awhile, rather than have a competitive match with other people.
*I did have tons of fun with UT2k4, and would like to get that running again on my system(as well as some old sp games), but that was really the only mp game I was into. Just need to make the time to try to figure it out.